SANAA — For decades, portraits of Ali Abdullah Saleh — clinging to the walls of libraries, mosques, coffee shops, courtyards and cafeterias — were part of the scenery in Sanaa, Yemen’s grubby capital. In the space of the past month, though, the autocrat’s mustachioed image has all but disappeared, hastily plastered over with glossy mug shots of a bald, solemn-looking man. The slogan underneath the portrait reads: "Together we will build a new Yemen."

For the first time in 33 years, Yemen has a new head of state. Swept into office by a controversial one-candidate vote last month, President Abd Rabu Monsour Hadi faces the difficult task of steering the country toward multi-party elections in 2014. It’s a job that would require huge political skill and authority even under the best of conditions. Yet Hadi is a political lightweight, an unlikely leader chosen primarily for his inoffensiveness. In Yemen, which endured decades of civil war in the twentieth century, Hadi is the safe pair of hands, the one political leader around whom warring factions were willing to rally.

Now Yemenis will see if he can live up to the challenge. In the year prior to last month’s referendum-style vote they experienced a bout of chaos that was daunting even by the standards of their tumultuous past. Yemen’s version of the Arab Spring shook the establishment to its core. A bomb attack on Saleh’s palace left him crippled. The armed forces splintered. An Islamist-dominated opposition took control of half the ministries in the new transitional government. And a faltering economy has left the population teetering on the verge of famine. Small wonder that many worry about the country sliding back into civil war.

Despite all the talk of democracy, elections, and unity government, Yemen remains largely under authoritarian rule, and that means that its further progress depends to a critical extent on the motives and capabilities of the man commanding its highest office. Yet the man upon whose shoulders the country’s fate rests remains an enigma to most of his compatriots. Hastily catapulted from the shadows into the spotlight, this veteran army general turned politician is now in charge of ruling one of the most fractured, impoverished, and conflict-ridden nations in the world.

Ask ordinary Yemenis about him and more often than not you’ll get the same lackluster response: "He was Saleh’s deputy." The fact that Hadi is still defined in relation to his predecessor is hardly surprising. From the day he seized power in a military coup in 1978, it was clear that Saleh, a master of political chess, was set on running a one-man show. The position of number two was to be a ceremonial posting, a job to which Hadi, a quiet, gentle man from humble beginnings and with no major political ambitions of his own, was well-suited. A decade’s worth of ribbon-snipping and dutiful photo-ops on the president’s behalf earned him the nickname "Mrs. Saleh." Others call him the "statue" of Yemeni politics, never noticed but always present.

"He’s like a vase you would put on your mantelpiece," says one senior politician from Islah, Yemen’s Islamist party. "It succeeds in looking nice and being part of the background at the same time."

Despite his long years as a protégé, Hadi is, in many ways, the antithesis of his former boss. Famed for his fiery, rambling, and at times incoherent speeches, Saleh, in contrast to camera-shy Hadi, exuded confidence. Indeed, the new president is known to sweat and fidget when he finds himself in public view. While Saleh’s immediate family and extended clan gobbled up high-level positions and the wealth that came with them, Hadi, whether by choice or political impotence, did not install his relatives in positions of power. "They don’t live a lavish lifestyle, they are very, very humble," said an official from Saleh’s ruling GPC party who did not wish to be named. "He is the only senior government official about whom I haven’t heard anyone complain of his embezzling or occupying land." So perhaps being Mr. Nobody could prove Hadi’s greatest strength — even with the opposition. "We are all willing to give him a chance," says Yassin Saeed Noman, leader of Yemen’s Socialist Party.

One can only hope this consensus holds until the 2014 election. If that happens, it will prove a remarkable victory over Yemen’s fractious legacy. As the optimists see it, it is precisely Hadi’s roots that could help to heal the painful rift between the country’s two former constituent halves. Hadi was born in 1945 in the village of Thukain in the heart of the rugged governorate of Abyan, then part of the former socialist republic of South Yemen (the only communist state the Middle East has ever had). Embarking on a long career in the military, he graduated at 19 from a military school in Aden before heading to Britain’s Sandhurst, and then to Cairo and the Soviet Union for spells of strategic military training. He returned from the USSR in 1980, and held several posts until the South merged with North Yemen a decade later.

Yet there are many in the South — above all the Hirak movement, now clamoring for a return to independence — who begrudge his reputation as a unifier. Hadi was one of a handful of cherry-picked southern leaders who profited from Yemen’s merger. (People from his own part of the country still refer to him as al-zumra, an Arabic word meaning "group" or "troop" that denotes those who betrayed the South to back Saleh.) When Yemen’s brutal civil war broke out in 1994, Hadi threw in his lot with Saleh, serving as the minister of defense and using his intimate knowledge of his home region to help vanquish former socialist comrades in the South. "He slaughtered us in 1994, and now you are electing him as president to try and make us feel better?" asks Karim Al-Dursi, a southern activist. Mr. Hadi has said that "dialogue and only dialogue" could resolve this long-standing grudge, but something more concrete will be needed if the country is to avoid being broken into two again.

Policymakers in Washington, meanwhile, are fixated on a more specific question: How will Hadi fare in Yemen’s decade-long U.S.-funded battle against Al-Qaeda in the Arabian Peninsula (AQAP), the local franchise of the network founded by Osama bin-Laden?

For years Saleh pulled off a remarkable balancing act, deftly persuading U.S. officials to continue a steady flow of billions of dollars to his government coffers as support for his "war on terror." He used the cash to push back against the jihadists but also to build heavily-equipped elite army units under control of his offspring that he could use to suppress local insurrections. Though Saleh’s relationship with Washington blew hot and cold, he never quite lost control. Last month, in an indication of his good standing, the U.S. government granted him permission to travel to New York for medical treatment.

For Hadi, by contrast, maintaining that cozy relationship with America is becoming increasingly difficult. A close rapport with Washington is whipping up discontent among a populace that views U.S. influence (not to mention drone attacks on Yemeni nationals) as an encroachment on their national sovereignty. Anti-U.S. protests are on the rise. (It’s a measure of that distrust that Yemenis have dubbed the U.S. ambassador "Sheikh Feierstein," in the belief that he is the real ruler in the land, not Hadi). Just to complicate matters further, militants linked to Al-Qaeda shot an American teacher this week.

None of this, however, has dissuaded Hadi from peddling the mantra that the U.S.-funded fight against extremism in his country is a "national and religious duty." Some Yemenis believe that Hadi has deeper motives for continuing the battle against the jihadists. "He will be stronger on Al Qaeda than Saleh," said the ruling party official. "He is a tribesman. They are occupying Abyan province, his birthplace. You think he is not insulted?"

Indeed, the tribal factor will be crucial to determining the success of Hadi’s caretaker reign. Saleh’s management and manipulation of tribal politics were a key to his success. Indeed, after three decades of rule, it was only in recent years that he lost the support of some of the largest tribal groupings (most notably the powerful Hashid confederation), when it became apparent that he was grooming his own son to take his place. Hadi’s own clan is linked to a relatively minor tribe, leaving him with little of the political weight that Saleh enjoyed. For the moment, the tribes are offering at least nominal support to Hadi, but it’s hard to say how long that will last.

He must also confront the legacy of Saleh’s nepotistic policies. Hadi has vowed to "restructure" the army, which many have taken as code for an impending campaign to rid the military of Saleh’s myriad relatives, who permeate its upper ranks. Saleh’s clansmen are deeply unpopular, and this week Hadi succumbed to months of rowdy demonstrations demanding the dismissal of Mohammed Saleh, the ex-president’s half-brother and commander of the air force, by vowing to fire him. Following through on that pledge could provide the new president with just the sort of clout he so desperately needs.

That implies, of course, that Hadi has the requisite political will to put his own stamp on a political establishment of which he is the product. Many observers wonder whether Hadi is truly in control, noting that Saleh, a master political intriguer, continues to exercise considerable influence behind the scenes. It was Saleh himself, after all, who described Hadi as a "safe pair of hands" when he handed power over to his ex-pupil last month.

Hadi has arguably displayed some admirable qualities while acting as one of the leaders of a brutally immoral regime, but he is also a man who spent his life obeying the military’s chain of command. Now he finds himself leading a civilian government on the path toward democracy — a state that most Yemenis can only dimly imagine. At best, say observers, he will maintain the status quo more or less intact; at worst, he will prove too weak to prevent the country from splintering again.

"I found him very human," says ex-minister Abdulrahman Al-Iryani. "He’s not like Ali Abdullah Saleh." He’s struck, he says, by Hadi’s relative modesty. But a caveat is quick to come: "If he can get through his two years without the country collapsing, that will be a huge accomplishment." For the moment, at least, President Hadi is Yemen’s only hope.